The survival of preterm infants has increased dramatically and has been associated with an increase in BPD. The incidence of BPD among extremely low birthweight infants ranges from 45% to 90%. Development of BPD is associated with both antenatal (maternal chorioamnionitis often due to Ureaplasma is related to BPD) and postnatal complications (oxygen toxicity, barotrauma, late onset infections). These insults appear to lead to an inflammatory response with resultant arrest of normal alveolar and vascular development. Multiple human studies support the role of inflammation in the development of BPD.